AQUEOUS RESIN COMPOSITION COMPRISING A POLYESTER-POLYURETHANE RESIN AND A DENDRITIC POLYOL

An aqueous resin composition comprises a polyester-polyurethane resin and a dendritic polyol. The polyester-polyurethane resin is obtained by reacting, in a one-stage process or multi-stage process, a reaction mixture comprising a polyester polyol with a number-average molecular weight Mn of >=400 g/mole to @6000 g/mole, at least one compound containing at least two isocyanate-reactive groups and at least one group capable of forming anions, and a polyisocyanate. The dendritic polyol is obtainable from a central initiator molecule or initiator polymer having at least one reactive hydroxyl group (X), which hydroxyl group (X) under formation of an initial tree structure is bonded to a reactive carboxyl group (Y) in a monomeric chain extender having the two reactive groups (X) and (Y), and wherein the chain extender has as least one carboxyl group (Y) and at least two hydroxyl groups (X) or hydroxyalkyl substituted hydroxyl groups (X).